Republican presidential hopeful Donald Trump has come under fire from his opponents in the last Republican debate before the all-important Super Tuesday contests.

The property billionaire entered Thursday's Texas showdown as the front runner but also as the man with the target on his back.

In the fiery make-or-break debate, the other candidates lined up to take aim.

Fighting to emerge as the Republican establishment, Trump alternative, Florida Senator Marco Rubio laid into his rival on everything from his healthcare plan (or lack of it) to his business record - delivering this zinger: "If he hadn’t inherited $200m, you know where Donald Trump would be? Selling watches in Manhattan."